// Copyright (C) 2006 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.


/**
 * @fileoverview
 * some functions for browser-side pretty printing of code contained in html.
 * <p>
 *
 * For a fairly comprehensive set of languages see the
 * <a href="http://google-code-prettify.googlecode.com/svn/trunk/README.html#langs">README</a>
 * file that came with this source.  At a minimum, the lexer should work on a
 * number of languages including C and friends, Java, Python, Bash, SQL, HTML,
 * XML, CSS, Javascript, and Makefiles.  It works passably on Ruby, PHP and Awk
 * and a subset of Perl, but, because of commenting conventions, doesn't work on
 * Smalltalk, Lisp-like, or CAML-like languages without an explicit lang class.
 * <p>
 * Usage: <ol>
 * <li> include this source file in an html page via
 *   {@code <script type="text/javascript" src="/path/to/prettify.js"></script>}
 * <li> define style rules.  See the example page for examples.
 * <li> mark the {@code <pre>} and {@code <code>} tags in your source with
 *    {@code class=prettyprint.}
 *    You can also use the (html deprecated) {@code <xmp>} tag, but the pretty
 *    printer needs to do more substantial DOM manipulations to support that, so
 *    some css styles may not be preserved.
 * </ol>
 * That's it.  I wanted to keep the API as simple as possible, so there's no
 * need to specify which language the code is in, but if you wish, you can add
 * another class to the {@code <pre>} or {@code <code>} element to specify the
 * language, as in {@code <pre class="prettyprint lang-java">}.  Any class that
 * starts with "lang-" followed by a file extension, specifies the file type.
 * See the "lang-*.js" files in this directory for code that implements
 * per-language file handlers.
 * <p>
 * Change log:<br>
 * cbeust, 2006/08/22
 * <blockquote>
 *   Java annotations (start with "@") are now captured as literals ("lit")
 * </blockquote>
 * @requires console
 */

// JSLint declarations
/*global console, document, navigator, setTimeout, window */

/**
 * Split {@code prettyPrint} into multiple timeouts so as not to interfere with
 * UI events.
 * If set to {@code false}, {@code prettyPrint()} is synchronous.
 */
window['PR_SHOULD_USE_CONTINUATION'] = true;

/** the number of characters between tab columns */
window['PR_TAB_WIDTH'] = 8;

/** Walks the DOM returning a properly escaped version of innerHTML.
 * @param {Node} node
 * @param {Array.<string>} out output buffer that receives chunks of HTML.
 */
window['PR_normalizedHtml']

    /** Contains functions for creating and registering new language handlers.
     * @type {Object}
     */
    = window['PR']

    /** Pretty print a chunk of code.
     *
     * @param {string} sourceCodeHtml code as html
     * @return {string} code as html, but prettier
     */
    = window['prettyPrintOne']
    /** Find all the {@code <pre>} and {@code <code>} tags in the DOM with
     * {@code class=prettyprint} and prettify them.
     * @param {Function?} opt_whenDone if specified, called when the last entry
     *     has been finished.
     */
    = window['prettyPrint'] = void 0;

/** browser detection. @extern @returns false if not IE, otherwise the major version. */
window['_pr_isIE6'] = function () {
    var ieVersion = navigator && navigator.userAgent &&
        navigator.userAgent.match(/\bMSIE ([678])\./);
    ieVersion = ieVersion ? +ieVersion[1] : false;
    window['_pr_isIE6'] = function () {
        return ieVersion;
    };
    return ieVersion;
};


(function () {
    // Keyword lists for various languages.
    var FLOW_CONTROL_KEYWORDS =
        "break continue do else for if return while ";
    var C_KEYWORDS = FLOW_CONTROL_KEYWORDS + "auto case char const default " +
        "double enum extern float goto int long register short signed sizeof " +
        "static struct switch typedef union unsigned void volatile ";
    var COMMON_KEYWORDS = C_KEYWORDS + "catch class delete false import " +
        "new operator private protected public this throw true try typeof ";
    var CPP_KEYWORDS = COMMON_KEYWORDS + "alignof align_union asm axiom bool " +
        "concept concept_map const_cast constexpr decltype " +
        "dynamic_cast explicit export friend inline late_check " +
        "mutable namespace nullptr reinterpret_cast static_assert static_cast " +
        "template typeid typename using virtual wchar_t where ";
    var JAVA_KEYWORDS = COMMON_KEYWORDS +
        "abstract boolean byte extends final finally implements import " +
        "instanceof null native package strictfp super synchronized throws " +
        "transient ";
    var CSHARP_KEYWORDS = JAVA_KEYWORDS +
        "as base by checked decimal delegate descending event " +
        "fixed foreach from group implicit in interface internal into is lock " +
        "object out override orderby params partial readonly ref sbyte sealed " +
        "stackalloc string select uint ulong unchecked unsafe ushort var ";
    var JSCRIPT_KEYWORDS = COMMON_KEYWORDS +
        "debugger eval export function get null set undefined var with " +
        "Infinity NaN ";
    var PERL_KEYWORDS = "caller delete die do dump elsif eval exit foreach for " +
        "goto if import last local my next no our print package redo require " +
        "sub undef unless until use wantarray while BEGIN END ";
    var PYTHON_KEYWORDS = FLOW_CONTROL_KEYWORDS + "and as assert class def del " +
        "elif except exec finally from global import in is lambda " +
        "nonlocal not or pass print raise try with yield " +
        "False True None ";
    var RUBY_KEYWORDS = FLOW_CONTROL_KEYWORDS + "alias and begin case class def" +
        " defined elsif end ensure false in module next nil not or redo rescue " +
        "retry self super then true undef unless until when yield BEGIN END ";
    var SH_KEYWORDS = FLOW_CONTROL_KEYWORDS + "case done elif esac eval fi " +
        "function in local set then until ";
    var ALL_KEYWORDS = (
        CPP_KEYWORDS + CSHARP_KEYWORDS + JSCRIPT_KEYWORDS + PERL_KEYWORDS +
        PYTHON_KEYWORDS + RUBY_KEYWORDS + SH_KEYWORDS);

    // token style names.  correspond to css classes
    /** token style for a string literal */
    var PR_STRING = 'str';
    /** token style for a keyword */
    var PR_KEYWORD = 'kwd';
    /** token style for a comment */
    var PR_COMMENT = 'com';
    /** token style for a type */
    var PR_TYPE = 'typ';
    /** token style for a literal value.  e.g. 1, null, true. */
    var PR_LITERAL = 'lit';
    /** token style for a punctuation string. */
    var PR_PUNCTUATION = 'pun';
    /** token style for a punctuation string. */
    var PR_PLAIN = 'pln';

    /** token style for an sgml tag. */
    var PR_TAG = 'tag';
    /** token style for a markup declaration such as a DOCTYPE. */
    var PR_DECLARATION = 'dec';
    /** token style for embedded source. */
    var PR_SOURCE = 'src';
    /** token style for an sgml attribute name. */
    var PR_ATTRIB_NAME = 'atn';
    /** token style for an sgml attribute value. */
    var PR_ATTRIB_VALUE = 'atv';

    /**
     * A class that indicates a section of markup that is not code, e.g. to allow
     * embedding of line numbers within code listings.
     */
    var PR_NOCODE = 'nocode';

    /** A set of tokens that can precede a regular expression literal in
     * javascript.
     * http://www.mozilla.org/js/language/js20/rationale/syntax.html has the full
     * list, but I've removed ones that might be problematic when seen in
     * languages that don't support regular expression literals.
     *
     * <p>Specifically, I've removed any keywords that can't precede a regexp
     * literal in a syntactically legal javascript program, and I've removed the
     * "in" keyword since it's not a keyword in many languages, and might be used
     * as a count of inches.
     *
     * <p>The link a above does not accurately describe EcmaScript rules since
     * it fails to distinguish between (a=++/b/i) and (a++/b/i) but it works
     * very well in practice.
     *
     * @private
     */
    var REGEXP_PRECEDER_PATTERN = function () {
        var preceders = [
            "!", "!=", "!==", "#", "%", "%=", "&", "&&", "&&=",
            "&=", "(", "*", "*=", /* "+", */ "+=", ",", /* "-", */ "-=",
            "->", /*".", "..", "...", handled below */ "/", "/=", ":", "::", ";",
            "<", "<<", "<<=", "<=", "=", "==", "===", ">",
            ">=", ">>", ">>=", ">>>", ">>>=", "?", "@", "[",
            "^", "^=", "^^", "^^=", "{", "|", "|=", "||",
            "||=", "~" /* handles =~ and !~ */,
            "break", "case", "continue", "delete",
            "do", "else", "finally", "instanceof",
            "return", "throw", "try", "typeof"
        ];
        var pattern = '(?:^^|[+-]';
        for (var i = 0; i < preceders.length; ++i) {
            pattern += '|' + preceders[i].replace(/([^=<>:&a-z])/g, '\\$1');
        }
        pattern += ')\\s*';  // matches at end, and matches empty string
        return pattern;
        // CAVEAT: this does not properly handle the case where a regular
        // expression immediately follows another since a regular expression may
        // have flags for case-sensitivity and the like.  Having regexp tokens
        // adjacent is not valid in any language I'm aware of, so I'm punting.
        // TODO: maybe style special characters inside a regexp as punctuation.
    }();

    // Define regexps here so that the interpreter doesn't have to create an
    // object each time the function containing them is called.
    // The language spec requires a new object created even if you don't access
    // the $1 members.
    var pr_amp = /&/g;
    var pr_lt = /</g;
    var pr_gt = />/g;
    var pr_quot = /\"/g;

    /** like textToHtml but escapes double quotes to be attribute safe. */
    function attribToHtml(str) {
        return str.replace(pr_amp, '&amp;')
            .replace(pr_lt, '&lt;')
            .replace(pr_gt, '&gt;')
            .replace(pr_quot, '&quot;');
    }

    /** escapest html special characters to html. */
    function textToHtml(str) {
        return str.replace(pr_amp, '&amp;')
            .replace(pr_lt, '&lt;')
            .replace(pr_gt, '&gt;');
    }


    var pr_ltEnt = /&lt;/g;
    var pr_gtEnt = /&gt;/g;
    var pr_aposEnt = /&apos;/g;
    var pr_quotEnt = /&quot;/g;
    var pr_ampEnt = /&amp;/g;
    var pr_nbspEnt = /&nbsp;/g;

    /** unescapes html to plain text. */
    function htmlToText(html) {
        var pos = html.indexOf('&');
        if (pos < 0) {
            return html;
        }
        // Handle numeric entities specially.  We can't use functional substitution
        // since that doesn't work in older versions of Safari.
        // These should be rare since most browsers convert them to normal chars.
        for (--pos; (pos = html.indexOf('&#', pos + 1)) >= 0;) {
            var end = html.indexOf(';', pos);
            if (end >= 0) {
                var num = html.substring(pos + 3, end);
                var radix = 10;
                if (num && num.charAt(0) === 'x') {
                    num = num.substring(1);
                    radix = 16;
                }
                var codePoint = parseInt(num, radix);
                if (!isNaN(codePoint)) {
                    html = (html.substring(0, pos) + String.fromCharCode(codePoint) +
                        html.substring(end + 1));
                }
            }
        }

        return html.replace(pr_ltEnt, '<')
            .replace(pr_gtEnt, '>')
            .replace(pr_aposEnt, "'")
            .replace(pr_quotEnt, '"')
            .replace(pr_nbspEnt, ' ')
            .replace(pr_ampEnt, '&');
    }

    /** is the given node's innerHTML normally unescaped? */
    function isRawContent(node) {
        return 'XMP' === node.tagName;
    }

    var newlineRe = /[\r\n]/g;

    /**
     * Are newlines and adjacent spaces significant in the given node's innerHTML?
     */
    function isPreformatted(node, content) {
        // PRE means preformatted, and is a very common case, so don't create
        // unnecessary computed style objects.
        if ('PRE' === node.tagName) {
            return true;
        }
        if (!newlineRe.test(content)) {
            return true;
        }  // Don't care
        var whitespace = '';
        // For disconnected nodes, IE has no currentStyle.
        if (node.currentStyle) {
            whitespace = node.currentStyle.whiteSpace;
        } else if (window.getComputedStyle) {
            // Firefox makes a best guess if node is disconnected whereas Safari
            // returns the empty string.
            whitespace = window.getComputedStyle(node, null).whiteSpace;
        }
        return !whitespace || whitespace === 'pre';
    }

    function normalizedHtml(node, out, opt_sortAttrs) {
        switch (node.nodeType) {
            case 1:  // an element
                var name = node.tagName.toLowerCase();

                out.push('<', name);
                var attrs = node.attributes;
                var n = attrs.length;
                if (n) {
                    if (opt_sortAttrs) {
                        var sortedAttrs = [];
                        for (var i = n; --i >= 0;) {
                            sortedAttrs[i] = attrs[i];
                        }
                        sortedAttrs.sort(function (a, b) {
                            return (a.name < b.name) ? -1 : a.name === b.name ? 0 : 1;
                        });
                        attrs = sortedAttrs;
                    }
                    for (var i = 0; i < n; ++i) {
                        var attr = attrs[i];
                        if (!attr.specified) {
                            continue;
                        }
                        out.push(' ', attr.name.toLowerCase(),
                            '="', attribToHtml(attr.value), '"');
                    }
                }
                out.push('>');
                for (var child = node.firstChild; child; child = child.nextSibling) {
                    normalizedHtml(child, out, opt_sortAttrs);
                }
                if (node.firstChild || !/^(?:br|link|img)$/.test(name)) {
                    out.push('<\/', name, '>');
                }
                break;
            case 3:
            case 4: // text
                out.push(textToHtml(node.nodeValue));
                break;
        }
    }

    /**
     * Given a group of {@link RegExp}s, returns a {@code RegExp} that globally
     * matches the union o the sets o strings matched d by the input RegExp.
     * Since it matches globally, if the input strings have a start-of-input
     * anchor (/^.../), it is ignored for the purposes of unioning.
     * @param {Array.<RegExp>} regexs non multiline, non-global regexs.
     * @return {RegExp} a global regex.
     */
    function combinePrefixPatterns(regexs) {
        var capturedGroupIndex = 0;

        var needToFoldCase = false;
        var ignoreCase = false;
        for (var i = 0, n = regexs.length; i < n; ++i) {
            var regex = regexs[i];
            if (regex.ignoreCase) {
                ignoreCase = true;
            } else if (/[a-z]/i.test(regex.source.replace(
                /\\u[0-9a-f]{4}|\\x[0-9a-f]{2}|\\[^ux]/gi, ''))) {
                needToFoldCase = true;
                ignoreCase = false;
                break;
            }
        }

        function decodeEscape(charsetPart) {
            if (charsetPart.charAt(0) !== '\\') {
                return charsetPart.charCodeAt(0);
            }
            switch (charsetPart.charAt(1)) {
                case 'b':
                    return 8;
                case 't':
                    return 9;
                case 'n':
                    return 0xa;
                case 'v':
                    return 0xb;
                case 'f':
                    return 0xc;
                case 'r':
                    return 0xd;
                case 'u':
                case 'x':
                    return parseInt(charsetPart.substring(2), 16)
                        || charsetPart.charCodeAt(1);
                case '0':
                case '1':
                case '2':
                case '3':
                case '4':
                case '5':
                case '6':
                case '7':
                    return parseInt(charsetPart.substring(1), 8);
                default:
                    return charsetPart.charCodeAt(1);
            }
        }

        function encodeEscape(charCode) {
            if (charCode < 0x20) {
                return (charCode < 0x10 ? '\\x0' : '\\x') + charCode.toString(16);
            }
            var ch = String.fromCharCode(charCode);
            if (ch === '\\' || ch === '-' || ch === '[' || ch === ']') {
                ch = '\\' + ch;
            }
            return ch;
        }

        function caseFoldCharset(charSet) {
            var charsetParts = charSet.substring(1, charSet.length - 1).match(
                new RegExp(
                    '\\\\u[0-9A-Fa-f]{4}'
                    + '|\\\\x[0-9A-Fa-f]{2}'
                    + '|\\\\[0-3][0-7]{0,2}'
                    + '|\\\\[0-7]{1,2}'
                    + '|\\\\[\\s\\S]'
                    + '|-'
                    + '|[^-\\\\]',
                    'g'));
            var groups = [];
            var ranges = [];
            var inverse = charsetParts[0] === '^';
            for (var i = inverse ? 1 : 0, n = charsetParts.length; i < n; ++i) {
                var p = charsetParts[i];
                switch (p) {
                    case '\\B':
                    case '\\b':
                    case '\\D':
                    case '\\d':
                    case '\\S':
                    case '\\s':
                    case '\\W':
                    case '\\w':
                        groups.push(p);
                        continue;
                }
                var start = decodeEscape(p);
                var end;
                if (i + 2 < n && '-' === charsetParts[i + 1]) {
                    end = decodeEscape(charsetParts[i + 2]);
                    i += 2;
                } else {
                    end = start;
                }
                ranges.push([start, end]);
                // If the range might intersect letters, then expand it.
                if (!(end < 65 || start > 122)) {
                    if (!(end < 65 || start > 90)) {
                        ranges.push([Math.max(65, start) | 32, Math.min(end, 90) | 32]);
                    }
                    if (!(end < 97 || start > 122)) {
                        ranges.push([Math.max(97, start) & ~32, Math.min(end, 122) & ~32]);
                    }
                }
            }

            // [[1, 10], [3, 4], [8, 12], [14, 14], [16, 16], [17, 17]]
            // -> [[1, 12], [14, 14], [16, 17]]
            ranges.sort(function (a, b) {
                return (a[0] - b[0]) || (b[1] - a[1]);
            });
            var consolidatedRanges = [];
            var lastRange = [NaN, NaN];
            for (var i = 0; i < ranges.length; ++i) {
                var range = ranges[i];
                if (range[0] <= lastRange[1] + 1) {
                    lastRange[1] = Math.max(lastRange[1], range[1]);
                } else {
                    consolidatedRanges.push(lastRange = range);
                }
            }

            var out = ['['];
            if (inverse) {
                out.push('^');
            }
            out.push.apply(out, groups);
            for (var i = 0; i < consolidatedRanges.length; ++i) {
                var range = consolidatedRanges[i];
                out.push(encodeEscape(range[0]));
                if (range[1] > range[0]) {
                    if (range[1] + 1 > range[0]) {
                        out.push('-');
                    }
                    out.push(encodeEscape(range[1]));
                }
            }
            out.push(']');
            return out.join('');
        }

        function allowAnywhereFoldCaseAndRenumberGroups(regex) {
            // Split into character sets, escape sequences, punctuation strings
            // like ('(', '(?:', ')', '^'), and runs of characters that do not
            // include any of the above.
            var parts = regex.source.match(
                new RegExp(
                    '(?:'
                    + '\\[(?:[^\\x5C\\x5D]|\\\\[\\s\\S])*\\]'  // a character set
                    + '|\\\\u[A-Fa-f0-9]{4}'  // a unicode escape
                    + '|\\\\x[A-Fa-f0-9]{2}'  // a hex escape
                    + '|\\\\[0-9]+'  // a back-reference or octal escape
                    + '|\\\\[^ux0-9]'  // other escape sequence
                    + '|\\(\\?[:!=]'  // start of a non-capturing group
                    + '|[\\(\\)\\^]'  // start/emd of a group, or line start
                    + '|[^\\x5B\\x5C\\(\\)\\^]+'  // run of other characters
                    + ')',
                    'g'));
            var n = parts.length;

            // Maps captured group numbers to the number they will occupy in
            // the output or to -1 if that has not been determined, or to
            // undefined if they need not be capturing in the output.
            var capturedGroups = [];

            // Walk over and identify back references to build the capturedGroups
            // mapping.
            for (var i = 0, groupIndex = 0; i < n; ++i) {
                var p = parts[i];
                if (p === '(') {
                    // groups are 1-indexed, so max group index is count of '('
                    ++groupIndex;
                } else if ('\\' === p.charAt(0)) {
                    var decimalValue = +p.substring(1);
                    if (decimalValue && decimalValue <= groupIndex) {
                        capturedGroups[decimalValue] = -1;
                    }
                }
            }

            // Renumber groups and reduce capturing groups to non-capturing groups
            // where possible.
            for (var i = 1; i < capturedGroups.length; ++i) {
                if (-1 === capturedGroups[i]) {
                    capturedGroups[i] = ++capturedGroupIndex;
                }
            }
            for (var i = 0, groupIndex = 0; i < n; ++i) {
                var p = parts[i];
                if (p === '(') {
                    ++groupIndex;
                    if (capturedGroups[groupIndex] === undefined) {
                        parts[i] = '(?:';
                    }
                } else if ('\\' === p.charAt(0)) {
                    var decimalValue = +p.substring(1);
                    if (decimalValue && decimalValue <= groupIndex) {
                        parts[i] = '\\' + capturedGroups[groupIndex];
                    }
                }
            }

            // Remove any prefix anchors so that the output will match anywhere.
            // ^^ really does mean an anchored match though.
            for (var i = 0, groupIndex = 0; i < n; ++i) {
                if ('^' === parts[i] && '^' !== parts[i + 1]) {
                    parts[i] = '';
                }
            }

            // Expand letters to groupts to handle mixing of case-sensitive and
            // case-insensitive patterns if necessary.
            if (regex.ignoreCase && needToFoldCase) {
                for (var i = 0; i < n; ++i) {
                    var p = parts[i];
                    var ch0 = p.charAt(0);
                    if (p.length >= 2 && ch0 === '[') {
                        parts[i] = caseFoldCharset(p);
                    } else if (ch0 !== '\\') {
                        // TODO: handle letters in numeric escapes.
                        parts[i] = p.replace(
                            /[a-zA-Z]/g,
                            function (ch) {
                                var cc = ch.charCodeAt(0);
                                return '[' + String.fromCharCode(cc & ~32, cc | 32) + ']';
                            });
                    }
                }
            }

            return parts.join('');
        }

        var rewritten = [];
        for (var i = 0, n = regexs.length; i < n; ++i) {
            var regex = regexs[i];
            if (regex.global || regex.multiline) {
                throw new Error('' + regex);
            }
            rewritten.push(
                '(?:' + allowAnywhereFoldCaseAndRenumberGroups(regex) + ')');
        }

        return new RegExp(rewritten.join('|'), ignoreCase ? 'gi' : 'g');
    }

    var PR_innerHtmlWorks = null;

    function getInnerHtml(node) {
        // inner html is hopelessly broken in Safari 2.0.4 when the content is
        // an html description of well formed XML and the containing tag is a PRE
        // tag, so we detect that case and emulate innerHTML.
        if (null === PR_innerHtmlWorks) {
            var testNode = document.createElement('PRE');
            testNode.appendChild(
                document.createTextNode('<!DOCTYPE foo PUBLIC "foo bar">\n<foo />'));
            PR_innerHtmlWorks = !/</.test(testNode.innerHTML);
        }

        if (PR_innerHtmlWorks) {
            var content = node.innerHTML;
            // XMP tags contain unescaped entities so require special handling.
            if (isRawContent(node)) {
                content = textToHtml(content);
            } else if (!isPreformatted(node, content)) {
                content = content.replace(/(<br\s*\/?>)[\r\n]+/g, '$1')
                    .replace(/(?:[\r\n]+[ \t]*)+/g, ' ');
            }
            return content;
        }

        var out = [];
        for (var child = node.firstChild; child; child = child.nextSibling) {
            normalizedHtml(child, out);
        }
        return out.join('');
    }

    /** returns a function that expand tabs to spaces.  This function can be fed
     * successive chunks of text, and will maintain its own internal state to
     * keep track of how tabs are expanded.
     * @return {function (string) : string} a function that takes
     *   plain text and return the text with tabs expanded.
     * @private
     */
    function makeTabExpander(tabWidth) {
        var SPACES = '                ';
        var charInLine = 0;

        return function (plainText) {
            // walk over each character looking for tabs and newlines.
            // On tabs, expand them.  On newlines, reset charInLine.
            // Otherwise increment charInLine
            var out = null;
            var pos = 0;
            for (var i = 0, n = plainText.length; i < n; ++i) {
                var ch = plainText.charAt(i);

                switch (ch) {
                    case '\t':
                        if (!out) {
                            out = [];
                        }
                        out.push(plainText.substring(pos, i));
                        // calculate how much space we need in front of this part
                        // nSpaces is the amount of padding -- the number of spaces needed
                        // to move us to the next column, where columns occur at factors of
                        // tabWidth.
                        var nSpaces = tabWidth - (charInLine % tabWidth);
                        charInLine += nSpaces;
                        for (; nSpaces >= 0; nSpaces -= SPACES.length) {
                            out.push(SPACES.substring(0, nSpaces));
                        }
                        pos = i + 1;
                        break;
                    case '\n':
                        charInLine = 0;
                        break;
                    default:
                        ++charInLine;
                }
            }
            if (!out) {
                return plainText;
            }
            out.push(plainText.substring(pos));
            return out.join('');
        };
    }

    var pr_chunkPattern = new RegExp(
        '[^<]+'  // A run of characters other than '<'
        + '|<\!--[\\s\\S]*?--\>'  // an HTML comment
        + '|<!\\[CDATA\\[[\\s\\S]*?\\]\\]>'  // a CDATA section
        // a probable tag that should not be highlighted
        + '|<\/?[a-zA-Z](?:[^>\"\']|\'[^\']*\'|\"[^\"]*\")*>'
        + '|<',  // A '<' that does not begin a larger chunk
        'g');
    var pr_commentPrefix = /^<\!--/;
    var pr_cdataPrefix = /^<!\[CDATA\[/;
    var pr_brPrefix = /^<br\b/i;
    var pr_tagNameRe = /^<(\/?)([a-zA-Z][a-zA-Z0-9]*)/;

    /** split markup into chunks of html tags (style null) and
     * plain text (style {@link #PR_PLAIN}), converting tags which are
     * significant for tokenization (<br>) into their textual equivalent.
     *
     * @param {string} s html where whitespace is considered significant.
     * @return {Object} source code and extracted tags.
     * @private
     */
    function extractTags(s) {
        // since the pattern has the 'g' modifier and defines no capturing groups,
        // this will return a list of all chunks which we then classify and wrap as
        // PR_Tokens
        var matches = s.match(pr_chunkPattern);
        var sourceBuf = [];
        var sourceBufLen = 0;
        var extractedTags = [];
        if (matches) {
            for (var i = 0, n = matches.length; i < n; ++i) {
                var match = matches[i];
                if (match.length > 1 && match.charAt(0) === '<') {
                    if (pr_commentPrefix.test(match)) {
                        continue;
                    }
                    if (pr_cdataPrefix.test(match)) {
                        // strip CDATA prefix and suffix.  Don't unescape since it's CDATA
                        sourceBuf.push(match.substring(9, match.length - 3));
                        sourceBufLen += match.length - 12;
                    } else if (pr_brPrefix.test(match)) {
                        // <br> tags are lexically significant so convert them to text.
                        // This is undone later.
                        sourceBuf.push('\n');
                        ++sourceBufLen;
                    } else {
                        if (match.indexOf(PR_NOCODE) >= 0 && isNoCodeTag(match)) {
                            // A <span class="nocode"> will start a section that should be
                            // ignored.  Continue walking the list until we see a matching end
                            // tag.
                            var name = match.match(pr_tagNameRe)[2];
                            var depth = 1;
                            var j;
                            for (j = i + 1; j < n; ++j) {
                                var name2 = matches[j].match(pr_tagNameRe);
                                if (name2 && name2[2] === name) {
                                    if (name2[1] === '/') {
                                        if (--depth === 0) {
                                            break;
                                        }
                                    } else {
                                        ++depth;
                                    }
                                }
                            }
                            if (j < n) {
                                extractedTags.push(
                                    sourceBufLen, matches.slice(i, j + 1).join(''));
                                i = j;
                            } else {  // Ignore unclosed sections.
                                extractedTags.push(sourceBufLen, match);
                            }
                        } else {
                            extractedTags.push(sourceBufLen, match);
                        }
                    }
                } else {
                    var literalText = htmlToText(match);
                    sourceBuf.push(literalText);
                    sourceBufLen += literalText.length;
                }
            }
        }
        return {source: sourceBuf.join(''), tags: extractedTags};
    }

    /** True if the given tag contains a class attribute with the nocode class. */
    function isNoCodeTag(tag) {
        return !!tag
            // First canonicalize the representation of attributes
            .replace(/\s(\w+)\s*=\s*(?:\"([^\"]*)\"|'([^\']*)'|(\S+))/g,
                ' $1="$2$3$4"')
            // Then look for the attribute we want.
            .match(/[cC][lL][aA][sS][sS]=\"[^\"]*\bnocode\b/);
    }

    /**
     * Apply the given language handler to sourceCode and add the resulting
     * decorations to out.
     * @param {number} basePos the index of sourceCode within the chunk of source
     *    whose decorations are already present on out.
     */
    function appendDecorations(basePos, sourceCode, langHandler, out) {
        if (!sourceCode) {
            return;
        }
        var job = {
            source: sourceCode,
            basePos: basePos
        };
        langHandler(job);
        out.push.apply(out, job.decorations);
    }

    /** Given triples of [style, pattern, context] returns a lexing function,
     * The lexing function interprets the patterns to find token boundaries and
     * returns a decoration list of the form
     * [index_0, style_0, index_1, style_1, ..., index_n, style_n]
     * where index_n is an index into the sourceCode, and style_n is a style
     * constant like PR_PLAIN.  index_n-1 <= index_n, and style_n-1 applies to
     * all characters in sourceCode[index_n-1:index_n].
     *
     * The stylePatterns is a list whose elements have the form
     * [style : string, pattern : RegExp, DEPRECATED, shortcut : string].
     *
     * Style is a style constant like PR_PLAIN, or can be a string of the
     * form 'lang-FOO', where FOO is a language extension describing the
     * language of the portion of the token in $1 after pattern executes.
     * E.g., if style is 'lang-lisp', and group 1 contains the text
     * '(hello (world))', then that portion of the token will be passed to the
     * registered lisp handler for formatting.
     * The text before and after group 1 will be restyled using this decorator
     * so decorators should take care that this doesn't result in infinite
     * recursion.  For example, the HTML lexer rule for SCRIPT elements looks
     * something like ['lang-js', /<[s]cript>(.+?)<\/script>/].  This may match
     * '<script>foo()<\/script>', which would cause the current decorator to
     * be called with '<script>' which would not match the same rule since
     * group 1 must not be empty, so it would be instead styled as PR_TAG by
     * the generic tag rule.  The handler registered for the 'js' extension would
     * then be called with 'foo()', and finally, the current decorator would
     * be called with '<\/script>' which would not match the original rule and
     * so the generic tag rule would identify it as a tag.
     *
     * Pattern must only match prefixes, and if it matches a prefix, then that
     * match is considered a token with the same style.
     *
     * Context is applied to the last non-whitespace, non-comment token
     * recognized.
     *
     * Shortcut is an optional string of characters, any of which, if the first
     * character, gurantee that this pattern and only this pattern matches.
     *
     * @param {Array} shortcutStylePatterns patterns that always start with
     *   a known character.  Must have a shortcut string.
     * @param {Array} fallthroughStylePatterns patterns that will be tried in
     *   order if the shortcut ones fail.  May have shortcuts.
     *
     * @return {function (Object)} a
     *   function that takes source code and returns a list of decorations.
     */
    function createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns) {
        var shortcuts = {};
        var tokenizer;
        (function () {
            var allPatterns = shortcutStylePatterns.concat(fallthroughStylePatterns);
            var allRegexs = [];
            var regexKeys = {};
            for (var i = 0, n = allPatterns.length; i < n; ++i) {
                var patternParts = allPatterns[i];
                var shortcutChars = patternParts[3];
                if (shortcutChars) {
                    for (var c = shortcutChars.length; --c >= 0;) {
                        shortcuts[shortcutChars.charAt(c)] = patternParts;
                    }
                }
                var regex = patternParts[1];
                var k = '' + regex;
                if (!regexKeys.hasOwnProperty(k)) {
                    allRegexs.push(regex);
                    regexKeys[k] = null;
                }
            }
            allRegexs.push(/[\0-\uffff]/);
            tokenizer = combinePrefixPatterns(allRegexs);
        })();

        var nPatterns = fallthroughStylePatterns.length;
        var notWs = /\S/;

        /**
         * Lexes job.source and produces an output array job.decorations of style
         * classes preceded by the position at which they start in job.source in
         * order.
         *
         * @param {Object} job an object like {@code
         *    source: {string} sourceText plain text,
         *    basePos: {int} position of job.source in the larger chunk of
         *        sourceCode.
         * }
         */
        var decorate = function (job) {
            var sourceCode = job.source, basePos = job.basePos;
            /** Even entries are positions in source in ascending order.  Odd enties
             * are style markers (e.g., PR_COMMENT) that run from that position until
             * the end.
             * @type {Array.<number|string>}
             */
            var decorations = [basePos, PR_PLAIN];
            var pos = 0;  // index into sourceCode
            var tokens = sourceCode.match(tokenizer) || [];
            var styleCache = {};

            for (var ti = 0, nTokens = tokens.length; ti < nTokens; ++ti) {
                var token = tokens[ti];
                var style = styleCache[token];
                var match = void 0;

                var isEmbedded;
                if (typeof style === 'string') {
                    isEmbedded = false;
                } else {
                    var patternParts = shortcuts[token.charAt(0)];
                    if (patternParts) {
                        match = token.match(patternParts[1]);
                        style = patternParts[0];
                    } else {
                        for (var i = 0; i < nPatterns; ++i) {
                            patternParts = fallthroughStylePatterns[i];
                            match = token.match(patternParts[1]);
                            if (match) {
                                style = patternParts[0];
                                break;
                            }
                        }

                        if (!match) {  // make sure that we make progress
                            style = PR_PLAIN;
                        }
                    }

                    isEmbedded = style.length >= 5 && 'lang-' === style.substring(0, 5);
                    if (isEmbedded && !(match && typeof match[1] === 'string')) {
                        isEmbedded = false;
                        style = PR_SOURCE;
                    }

                    if (!isEmbedded) {
                        styleCache[token] = style;
                    }
                }

                var tokenStart = pos;
                pos += token.length;

                if (!isEmbedded) {
                    decorations.push(basePos + tokenStart, style);
                } else {  // Treat group 1 as an embedded block of source code.
                    var embeddedSource = match[1];
                    var embeddedSourceStart = token.indexOf(embeddedSource);
                    var embeddedSourceEnd = embeddedSourceStart + embeddedSource.length;
                    if (match[2]) {
                        // If embeddedSource can be blank, then it would match at the
                        // beginning which would cause us to infinitely recurse on the
                        // entire token, so we catch the right context in match[2].
                        embeddedSourceEnd = token.length - match[2].length;
                        embeddedSourceStart = embeddedSourceEnd - embeddedSource.length;
                    }
                    var lang = style.substring(5);
                    // Decorate the left of the embedded source
                    appendDecorations(
                        basePos + tokenStart,
                        token.substring(0, embeddedSourceStart),
                        decorate, decorations);
                    // Decorate the embedded source
                    appendDecorations(
                        basePos + tokenStart + embeddedSourceStart,
                        embeddedSource,
                        langHandlerForExtension(lang, embeddedSource),
                        decorations);
                    // Decorate the right of the embedded section
                    appendDecorations(
                        basePos + tokenStart + embeddedSourceEnd,
                        token.substring(embeddedSourceEnd),
                        decorate, decorations);
                }
            }
            job.decorations = decorations;
        };
        return decorate;
    }

    /** returns a function that produces a list of decorations from source text.
     *
     * This code treats ", ', and ` as string delimiters, and \ as a string
     * escape.  It does not recognize perl's qq() style strings.
     * It has no special handling for double delimiter escapes as in basic, or
     * the tripled delimiters used in python, but should work on those regardless
     * although in those cases a single string literal may be broken up into
     * multiple adjacent string literals.
     *
     * It recognizes C, C++, and shell style comments.
     *
     * @param {Object} options a set of optional parameters.
     * @return {function (Object)} a function that examines the source code
     *     in the input job and builds the decoration list.
     */
    function sourceDecorator(options) {
        var shortcutStylePatterns = [], fallthroughStylePatterns = [];
        if (options['tripleQuotedStrings']) {
            // '''multi-line-string''', 'single-line-string', and double-quoted
            shortcutStylePatterns.push(
                [PR_STRING, /^(?:\'\'\'(?:[^\'\\]|\\[\s\S]|\'{1,2}(?=[^\']))*(?:\'\'\'|$)|\"\"\"(?:[^\"\\]|\\[\s\S]|\"{1,2}(?=[^\"]))*(?:\"\"\"|$)|\'(?:[^\\\']|\\[\s\S])*(?:\'|$)|\"(?:[^\\\"]|\\[\s\S])*(?:\"|$))/,
                    null, '\'"']);
        } else if (options['multiLineStrings']) {
            // 'multi-line-string', "multi-line-string"
            shortcutStylePatterns.push(
                [PR_STRING, /^(?:\'(?:[^\\\']|\\[\s\S])*(?:\'|$)|\"(?:[^\\\"]|\\[\s\S])*(?:\"|$)|\`(?:[^\\\`]|\\[\s\S])*(?:\`|$))/,
                    null, '\'"`']);
        } else {
            // 'single-line-string', "single-line-string"
            shortcutStylePatterns.push(
                [PR_STRING,
                    /^(?:\'(?:[^\\\'\r\n]|\\.)*(?:\'|$)|\"(?:[^\\\"\r\n]|\\.)*(?:\"|$))/,
                    null, '"\'']);
        }
        if (options['verbatimStrings']) {
            // verbatim-string-literal production from the C# grammar.  See issue 93.
            fallthroughStylePatterns.push(
                [PR_STRING, /^@\"(?:[^\"]|\"\")*(?:\"|$)/, null]);
        }
        if (options['hashComments']) {
            if (options['cStyleComments']) {
                // Stop C preprocessor declarations at an unclosed open comment
                shortcutStylePatterns.push(
                    [PR_COMMENT, /^#(?:(?:define|elif|else|endif|error|ifdef|include|ifndef|line|pragma|undef|warning)\b|[^\r\n]*)/,
                        null, '#']);
                fallthroughStylePatterns.push(
                    [PR_STRING,
                        /^<(?:(?:(?:\.\.\/)*|\/?)(?:[\w-]+(?:\/[\w-]+)+)?[\w-]+\.h|[a-z]\w*)>/,
                        null]);
            } else {
                shortcutStylePatterns.push([PR_COMMENT, /^#[^\r\n]*/, null, '#']);
            }
        }
        if (options['cStyleComments']) {
            fallthroughStylePatterns.push([PR_COMMENT, /^\/\/[^\r\n]*/, null]);
            fallthroughStylePatterns.push(
                [PR_COMMENT, /^\/\*[\s\S]*?(?:\*\/|$)/, null]);
        }
        if (options['regexLiterals']) {
            var REGEX_LITERAL = (
                // A regular expression literal starts with a slash that is
                // not followed by * or / so that it is not confused with
                // comments.
                '/(?=[^/*])'
                // and then contains any number of raw characters,
                + '(?:[^/\\x5B\\x5C]'
                // escape sequences (\x5C),
                + '|\\x5C[\\s\\S]'
                // or non-nesting character sets (\x5B\x5D);
                + '|\\x5B(?:[^\\x5C\\x5D]|\\x5C[\\s\\S])*(?:\\x5D|$))+'
                // finally closed by a /.
                + '/');
            fallthroughStylePatterns.push(
                ['lang-regex',
                    new RegExp('^' + REGEXP_PRECEDER_PATTERN + '(' + REGEX_LITERAL + ')')
                ]);
        }

        var keywords = options['keywords'].replace(/^\s+|\s+$/g, '');
        if (keywords.length) {
            fallthroughStylePatterns.push(
                [PR_KEYWORD,
                    new RegExp('^(?:' + keywords.replace(/\s+/g, '|') + ')\\b'), null]);
        }

        shortcutStylePatterns.push([PR_PLAIN, /^\s+/, null, ' \r\n\t\xA0']);
        fallthroughStylePatterns.push(
            // TODO(mikesamuel): recognize non-latin letters and numerals in idents
            [PR_LITERAL, /^@[a-z_$][a-z_$@0-9]*/i, null],
            [PR_TYPE, /^@?[A-Z]+[a-z][A-Za-z_$@0-9]*/, null],
            [PR_PLAIN, /^[a-z_$][a-z_$@0-9]*/i, null],
            [PR_LITERAL,
                new RegExp(
                    '^(?:'
                    // A hex number
                    + '0x[a-f0-9]+'
                    // or an octal or decimal number,
                    + '|(?:\\d(?:_\\d+)*\\d*(?:\\.\\d*)?|\\.\\d\\+)'
                    // possibly in scientific notation
                    + '(?:e[+\\-]?\\d+)?'
                    + ')'
                    // with an optional modifier like UL for unsigned long
                    + '[a-z]*', 'i'),
                null, '0123456789'],
            [PR_PUNCTUATION, /^.[^\s\w\.$@\'\"\`\/\#]*/, null]);

        return createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns);
    }

    var decorateSource = sourceDecorator({
        'keywords': ALL_KEYWORDS,
        'hashComments': true,
        'cStyleComments': true,
        'multiLineStrings': true,
        'regexLiterals': true
    });

    /** Breaks {@code job.source} around style boundaries in
     * {@code job.decorations} while re-interleaving {@code job.extractedTags},
     * and leaves the result in {@code job.prettyPrintedHtml}.
     * @param {Object} job like {
     *    source: {string} source as plain text,
     *    extractedTags: {Array.<number|string>} extractedTags chunks of raw
     *                   html preceded by their position in {@code job.source}
     *                   in order
     *    decorations: {Array.<number|string} an array of style classes preceded
     *                 by the position at which they start in job.source in order
     * }
     * @private
     */
    function recombineTagsAndDecorations(job) {
        var sourceText = job.source;
        var extractedTags = job.extractedTags;
        var decorations = job.decorations;

        var html = [];
        // index past the last char in sourceText written to html
        var outputIdx = 0;

        var openDecoration = null;
        var currentDecoration = null;
        var tagPos = 0;  // index into extractedTags
        var decPos = 0;  // index into decorations
        var tabExpander = makeTabExpander(window['PR_TAB_WIDTH']);

        var adjacentSpaceRe = /([\r\n ]) /g;
        var startOrSpaceRe = /(^| ) /gm;
        var newlineRe = /\r\n?|\n/g;
        var trailingSpaceRe = /[ \r\n]$/;
        var lastWasSpace = true;  // the last text chunk emitted ended with a space.

        // See bug 71 and http://stackoverflow.com/questions/136443/why-doesnt-ie7-
        var isIE678 = window['_pr_isIE6']();
        var lineBreakHtml = (
            isIE678
                ? (job.sourceNode.tagName === 'PRE'
                    // Use line feeds instead of <br>s so that copying and pasting works
                    // on IE.
                    // Doing this on other browsers breaks lots of stuff since \r\n is
                    // treated as two newlines on Firefox.
                    ? (isIE678 === 6 ? '&#160;\r\n' :
                        isIE678 === 7 ? '&#160;<br>\r' : '&#160;\r')
                    // IE collapses multiple adjacent <br>s into 1 line break.
                    // Prefix every newline with '&#160;' to prevent such behavior.
                    // &nbsp; is the same as &#160; but works in XML as well as HTML.
                    : '&#160;<br />')
                : '<br />');

        // Look for a class like linenums or linenums:<n> where <n> is the 1-indexed
        // number of the first line.
        var numberLines = job.sourceNode.className.match(/\blinenums\b(?::(\d+))?/);
        var lineBreaker;
        if (numberLines) {
            var lineBreaks = [];
            for (var i = 0; i < 10; ++i) {
                lineBreaks[i] = lineBreakHtml + '</li><li class="L' + i + '">';
            }
            var lineNum = numberLines[1] && numberLines[1].length
                ? numberLines[1] - 1 : 0;  // Lines are 1-indexed
            html.push('<ol class="linenums"><li class="L', (lineNum) % 10, '"');
            if (lineNum) {
                html.push(' value="', lineNum + 1, '"');
            }
            html.push('>');
            lineBreaker = function () {
                var lb = lineBreaks[++lineNum % 10];
                // If a decoration is open, we need to close it before closing a list-item
                // and reopen it on the other side of the list item.
                return openDecoration
                    ? ('</span>' + lb + '<span class="' + openDecoration + '">') : lb;
            };
        } else {
            lineBreaker = lineBreakHtml;
        }

        // A helper function that is responsible for opening sections of decoration
        // and outputing properly escaped chunks of source
        function emitTextUpTo(sourceIdx) {
            if (sourceIdx > outputIdx) {
                if (openDecoration && openDecoration !== currentDecoration) {
                    // Close the current decoration
                    html.push('</span>');
                    openDecoration = null;
                }
                if (!openDecoration && currentDecoration) {
                    openDecoration = currentDecoration;
                    html.push('<span class="', openDecoration, '">');
                }
                // This interacts badly with some wikis which introduces paragraph tags
                // into pre blocks for some strange reason.
                // It's necessary for IE though which seems to lose the preformattedness
                // of <pre> tags when their innerHTML is assigned.
                // http://stud3.tuwien.ac.at/~e0226430/innerHtmlQuirk.html
                // and it serves to undo the conversion of <br>s to newlines done in
                // chunkify.
                var htmlChunk = textToHtml(
                    tabExpander(sourceText.substring(outputIdx, sourceIdx)))
                    .replace(lastWasSpace
                        ? startOrSpaceRe
                        : adjacentSpaceRe, '$1&#160;');
                // Keep track of whether we need to escape space at the beginning of the
                // next chunk.
                lastWasSpace = trailingSpaceRe.test(htmlChunk);
                html.push(htmlChunk.replace(newlineRe, lineBreaker));
                outputIdx = sourceIdx;
            }
        }

        while (true) {
            // Determine if we're going to consume a tag this time around.  Otherwise
            // we consume a decoration or exit.
            var outputTag;
            if (tagPos < extractedTags.length) {
                if (decPos < decorations.length) {
                    // Pick one giving preference to extractedTags since we shouldn't open
                    // a new style that we're going to have to immediately close in order
                    // to output a tag.
                    outputTag = extractedTags[tagPos] <= decorations[decPos];
                } else {
                    outputTag = true;
                }
            } else {
                outputTag = false;
            }
            // Consume either a decoration or a tag or exit.
            if (outputTag) {
                emitTextUpTo(extractedTags[tagPos]);
                if (openDecoration) {
                    // Close the current decoration
                    html.push('</span>');
                    openDecoration = null;
                }
                html.push(extractedTags[tagPos + 1]);
                tagPos += 2;
            } else if (decPos < decorations.length) {
                emitTextUpTo(decorations[decPos]);
                currentDecoration = decorations[decPos + 1];
                decPos += 2;
            } else {
                break;
            }
        }
        emitTextUpTo(sourceText.length);
        if (openDecoration) {
            html.push('</span>');
        }
        if (numberLines) {
            html.push('</li></ol>');
        }
        job.prettyPrintedHtml = html.join('');
    }

    /** Maps language-specific file extensions to handlers. */
    var langHandlerRegistry = {};

    /** Register a language handler for the given file extensions.
     * @param {function (Object)} handler a function from source code to a list
     *      of decorations.  Takes a single argument job which describes the
     *      state of the computation.   The single parameter has the form
     *      {@code {
     *        source: {string} as plain text.
     *        decorations: {Array.<number|string>} an array of style classes
     *                     preceded by the position at which they start in
     *                     job.source in order.
     *                     The language handler should assigned this field.
     *        basePos: {int} the position of source in the larger source chunk.
     *                 All positions in the output decorations array are relative
     *                 to the larger source chunk.
     *      } }
     * @param {Array.<string>} fileExtensions
     */
    function registerLangHandler(handler, fileExtensions) {
        for (var i = fileExtensions.length; --i >= 0;) {
            var ext = fileExtensions[i];
            if (!langHandlerRegistry.hasOwnProperty(ext)) {
                langHandlerRegistry[ext] = handler;
            } else if ('console' in window) {
                console['warn']('cannot override language handler %s', ext);
            }
        }
    }

    function langHandlerForExtension(extension, source) {
        if (!(extension && langHandlerRegistry.hasOwnProperty(extension))) {
            // Treat it as markup if the first non whitespace character is a < and
            // the last non-whitespace character is a >.
            extension = /^\s*</.test(source)
                ? 'default-markup'
                : 'default-code';
        }
        return langHandlerRegistry[extension];
    }

    registerLangHandler(decorateSource, ['default-code']);
    registerLangHandler(
        createSimpleLexer(
            [],
            [
                [PR_PLAIN, /^[^<?]+/],
                [PR_DECLARATION, /^<!\w[^>]*(?:>|$)/],
                [PR_COMMENT, /^<\!--[\s\S]*?(?:-\->|$)/],
                // Unescaped content in an unknown language
                ['lang-', /^<\?([\s\S]+?)(?:\?>|$)/],
                ['lang-', /^<%([\s\S]+?)(?:%>|$)/],
                [PR_PUNCTUATION, /^(?:<[%?]|[%?]>)/],
                ['lang-', /^<xmp\b[^>]*>([\s\S]+?)<\/xmp\b[^>]*>/i],
                // Unescaped content in javascript.  (Or possibly vbscript).
                ['lang-js', /^<script\b[^>]*>([\s\S]*?)(<\/script\b[^>]*>)/i],
                // Contains unescaped stylesheet content
                ['lang-css', /^<style\b[^>]*>([\s\S]*?)(<\/style\b[^>]*>)/i],
                ['lang-in.tag', /^(<\/?[a-z][^<>]*>)/i]
            ]),
        ['default-markup', 'htm', 'html', 'mxml', 'xhtml', 'xml', 'xsl']);
    registerLangHandler(
        createSimpleLexer(
            [
                [PR_PLAIN, /^[\s]+/, null, ' \t\r\n'],
                [PR_ATTRIB_VALUE, /^(?:\"[^\"]*\"?|\'[^\']*\'?)/, null, '\"\'']
            ],
            [
                [PR_TAG, /^^<\/?[a-z](?:[\w.:-]*\w)?|\/?>$/i],
                [PR_ATTRIB_NAME, /^(?!style[\s=]|on)[a-z](?:[\w:-]*\w)?/i],
                ['lang-uq.val', /^=\s*([^>\'\"\s]*(?:[^>\'\"\s\/]|\/(?=\s)))/],
                [PR_PUNCTUATION, /^[=<>\/]+/],
                ['lang-js', /^on\w+\s*=\s*\"([^\"]+)\"/i],
                ['lang-js', /^on\w+\s*=\s*\'([^\']+)\'/i],
                ['lang-js', /^on\w+\s*=\s*([^\"\'>\s]+)/i],
                ['lang-css', /^style\s*=\s*\"([^\"]+)\"/i],
                ['lang-css', /^style\s*=\s*\'([^\']+)\'/i],
                ['lang-css', /^style\s*=\s*([^\"\'>\s]+)/i]
            ]),
        ['in.tag']);
    registerLangHandler(
        createSimpleLexer([], [[PR_ATTRIB_VALUE, /^[\s\S]+/]]), ['uq.val']);
    registerLangHandler(sourceDecorator({
        'keywords': CPP_KEYWORDS,
        'hashComments': true,
        'cStyleComments': true
    }), ['c', 'cc', 'cpp', 'cxx', 'cyc', 'm']);
    registerLangHandler(sourceDecorator({
        'keywords': 'null true false'
    }), ['json']);
    registerLangHandler(sourceDecorator({
        'keywords': CSHARP_KEYWORDS,
        'hashComments': true,
        'cStyleComments': true,
        'verbatimStrings': true
    }), ['cs']);
    registerLangHandler(sourceDecorator({
        'keywords': JAVA_KEYWORDS,
        'cStyleComments': true
    }), ['java']);
    registerLangHandler(sourceDecorator({
        'keywords': SH_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true
    }), ['bsh', 'csh', 'sh']);
    registerLangHandler(sourceDecorator({
        'keywords': PYTHON_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true,
        'tripleQuotedStrings': true
    }), ['cv', 'py']);
    registerLangHandler(sourceDecorator({
        'keywords': PERL_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true,
        'regexLiterals': true
    }), ['perl', 'pl', 'pm']);
    registerLangHandler(sourceDecorator({
        'keywords': RUBY_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true,
        'regexLiterals': true
    }), ['rb']);
    registerLangHandler(sourceDecorator({
        'keywords': JSCRIPT_KEYWORDS,
        'cStyleComments': true,
        'regexLiterals': true
    }), ['js']);
    registerLangHandler(
        createSimpleLexer([], [[PR_STRING, /^[\s\S]+/]]), ['regex']);

    function applyDecorator(job) {
        var sourceCodeHtml = job.sourceCodeHtml;
        var opt_langExtension = job.langExtension;

        // Prepopulate output in case processing fails with an exception.
        job.prettyPrintedHtml = sourceCodeHtml;

        try {
            // Extract tags, and convert the source code to plain text.
            var sourceAndExtractedTags = extractTags(sourceCodeHtml);
            /** Plain text. @type {string} */
            var source = sourceAndExtractedTags.source;
            job.source = source;
            job.basePos = 0;

            /** Even entries are positions in source in ascending order.  Odd entries
             * are tags that were extracted at that position.
             * @type {Array.<number|string>}
             */
            job.extractedTags = sourceAndExtractedTags.tags;

            // Apply the appropriate language handler
            langHandlerForExtension(opt_langExtension, source)(job);
            // Integrate the decorations and tags back into the source code to produce
            // a decorated html string which is left in job.prettyPrintedHtml.
            recombineTagsAndDecorations(job);
        } catch (e) {
            if ('console' in window) {
                console['log'](e && e['stack'] ? e['stack'] : e);
            }
        }
    }

    function prettyPrintOne(sourceCodeHtml, opt_langExtension) {
        var job = {
            sourceCodeHtml: sourceCodeHtml,
            langExtension: opt_langExtension
        };
        applyDecorator(job);
        return job.prettyPrintedHtml;
    }

    function prettyPrint(opt_whenDone) {
        function byTagName(tn) {
            return document.getElementsByTagName(tn);
        }

        // fetch a list of nodes to rewrite
        var codeSegments = [byTagName('pre'), byTagName('code'), byTagName('xmp')];
        var elements = [];
        for (var i = 0; i < codeSegments.length; ++i) {
            for (var j = 0, n = codeSegments[i].length; j < n; ++j) {
                elements.push(codeSegments[i][j]);
            }
        }
        codeSegments = null;

        var clock = Date;
        if (!clock['now']) {
            clock = {
                'now': function () {
                    return (new Date).getTime();
                }
            };
        }

        // The loop is broken into a series of continuations to make sure that we
        // don't make the browser unresponsive when rewriting a large page.
        var k = 0;
        var prettyPrintingJob;

        function doWork() {
            var endTime = (window['PR_SHOULD_USE_CONTINUATION'] ?
                clock.now() + 250 /* ms */ :
                Infinity);
            for (; k < elements.length && clock.now() < endTime; k++) {
                var cs = elements[k];
                // [JACOCO] 'prettyprint' -> 'source'
                if (cs.className && cs.className.indexOf('source') >= 0) {
                    // If the classes includes a language extensions, use it.
                    // Language extensions can be specified like
                    //     <pre class="prettyprint lang-cpp">
                    // the language extension "cpp" is used to find a language handler as
                    // passed to PR_registerLangHandler.
                    var langExtension = cs.className.match(/\blang-(\w+)\b/);
                    if (langExtension) {
                        langExtension = langExtension[1];
                    }

                    // make sure this is not nested in an already prettified element
                    var nested = false;
                    for (var p = cs.parentNode; p; p = p.parentNode) {
                        if ((p.tagName === 'pre' || p.tagName === 'code' ||
                                p.tagName === 'xmp') &&
                            // [JACOCO] 'prettyprint' -> 'source'
                            p.className && p.className.indexOf('source') >= 0) {
                            nested = true;
                            break;
                        }
                    }
                    if (!nested) {
                        // fetch the content as a snippet of properly escaped HTML.
                        // Firefox adds newlines at the end.
                        var content = getInnerHtml(cs);
                        content = content.replace(/(?:\r\n?|\n)$/, '');

                        // do the pretty printing
                        prettyPrintingJob = {
                            sourceCodeHtml: content,
                            langExtension: langExtension,
                            sourceNode: cs
                        };
                        applyDecorator(prettyPrintingJob);
                        replaceWithPrettyPrintedHtml();
                    }
                }
            }
            if (k < elements.length) {
                // finish up in a continuation
                setTimeout(doWork, 250);
            } else if (opt_whenDone) {
                opt_whenDone();
            }
        }

        function replaceWithPrettyPrintedHtml() {
            var newContent = prettyPrintingJob.prettyPrintedHtml;
            if (!newContent) {
                return;
            }
            var cs = prettyPrintingJob.sourceNode;

            // push the prettified html back into the tag.
            if (!isRawContent(cs)) {
                // just replace the old html with the new
                cs.innerHTML = newContent;
            } else {
                // we need to change the tag to a <pre> since <xmp>s do not allow
                // embedded tags such as the span tags used to attach styles to
                // sections of source code.
                var pre = document.createElement('PRE');
                for (var i = 0; i < cs.attributes.length; ++i) {
                    var a = cs.attributes[i];
                    if (a.specified) {
                        var aname = a.name.toLowerCase();
                        if (aname === 'class') {
                            pre.className = a.value;  // For IE 6
                        } else {
                            pre.setAttribute(a.name, a.value);
                        }
                    }
                }
                pre.innerHTML = newContent;

                // remove the old
                cs.parentNode.replaceChild(pre, cs);
                cs = pre;
            }
        }

        doWork();
    }

    window['PR_normalizedHtml'] = normalizedHtml;
    window['prettyPrintOne'] = prettyPrintOne;
    window['prettyPrint'] = prettyPrint;
    window['PR'] = {
        'combinePrefixPatterns': combinePrefixPatterns,
        'createSimpleLexer': createSimpleLexer,
        'registerLangHandler': registerLangHandler,
        'sourceDecorator': sourceDecorator,
        'PR_ATTRIB_NAME': PR_ATTRIB_NAME,
        'PR_ATTRIB_VALUE': PR_ATTRIB_VALUE,
        'PR_COMMENT': PR_COMMENT,
        'PR_DECLARATION': PR_DECLARATION,
        'PR_KEYWORD': PR_KEYWORD,
        'PR_LITERAL': PR_LITERAL,
        'PR_NOCODE': PR_NOCODE,
        'PR_PLAIN': PR_PLAIN,
        'PR_PUNCTUATION': PR_PUNCTUATION,
        'PR_SOURCE': PR_SOURCE,
        'PR_STRING': PR_STRING,
        'PR_TAG': PR_TAG,
        'PR_TYPE': PR_TYPE
    };
})();
